public class Hash {
    private Node[] arr= new Node [20];
    public void add(int x){
        Node n=new Node();
        n.value=x;
        n.next=null;
        int m=(x+21)%20;
        if(arr[m]==null){
            arr[m]=n;
        }else{
            while(arr[m].next!=null){
                arr[m]=arr[m].next;
            }
            arr[m].next=n;
        }
    }
    public String get(int x){
        int m=(x+21)%20;
        if(arr[m]==null){
            return "空";
        }else{
            return arr[m].toString();
        }
    }
}
